Some Colorful Expressions

Lily White:
A lily is a type of flower (see picture). The expression lily-white refers something that is pure, innocent, without fault, or without blame. We often use this to talk about whether politicians and other people are honest or not.
- "Politicians have problems appearing lily white when they accept money from wealthy, influential people."
- "Everyone thought that the university president was lily-white until the scandal broke (became known)."

"Lily-white" has a second meaning that relates to race. It is used to describe something that excludes (does not allow) non-white people.
- "This club has been lily-white for 200 years and they don't plan to change that even under community pressure."
- "Few neighborhoods in Los Angeles are still lily-white."
…

Green:

The word green is closely related to the English verb "to grow". It is used to describe plants or the ocean. Sometimes it can also describe someone who is inexperienced, jealous, or sick.

In America, green is a slang term for money, among other things. Several colloquialisms have derived from these meanings, such as :

"green around the gills", a phrase used to describe a person who looks ill.

However, green has some other meanings in other cultures.

Being green means being inexperienced, new to doing something or performing a job.
- "The medical student is too green to perform this procedure without help."
- "The new manager will seem a little green until she learns the job."

These days, green has a second meaning. We use green to refer to things that are not harmful to the environment.
- "We're turning this into a green house by buying energy-efficient appliances (refrigerator, stove, etc.) and planting vegetables instead of grass.
- "By buying hybrid cars (cars that use gasoline and electricity), our company is taking the first step toward going green."

Green: we can say of a book or a movie is erotic, but if we say that it is green, then we mean that it is a book or movie of low quality.…

Green with envy to refers to someone who envys somebody else sucess

White elephant which means something costly but hopeless ( not useful)

white knight- business usage, specially now a days- which means somebody who assist a company financially in order to bail the company out.

True colors means the true identity of a person. Finally , Jack showed me his true color.